diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
index fdbd1d7539..22f7832780 100644
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -1500,6 +1500,7 @@ phutil_register_library_map(array(
     'PHUIListItemView' => 'view/phui/PHUIListItemView.php',
     'PHUIListView' => 'view/phui/PHUIListView.php',
     'PHUIListViewTestCase' => 'view/layout/__tests__/PHUIListViewTestCase.php',
+    'PHUIMainMenuView' => 'view/phui/PHUIMainMenuView.php',
     'PHUIObjectBoxView' => 'view/phui/PHUIObjectBoxView.php',
     'PHUIObjectItemListExample' => 'applications/uiexample/examples/PHUIObjectItemListExample.php',
     'PHUIObjectItemListView' => 'view/phui/PHUIObjectItemListView.php',
@@ -1722,6 +1723,7 @@ phutil_register_library_map(array(
     'PhabricatorAuthListController' => 'applications/auth/controller/config/PhabricatorAuthListController.php',
     'PhabricatorAuthLoginController' => 'applications/auth/controller/PhabricatorAuthLoginController.php',
     'PhabricatorAuthLoginHandler' => 'applications/auth/handler/PhabricatorAuthLoginHandler.php',
+    'PhabricatorAuthMainMenuBarExtension' => 'applications/auth/extension/PhabricatorAuthMainMenuBarExtension.php',
     'PhabricatorAuthManagementCachePKCS8Workflow' => 'applications/auth/management/PhabricatorAuthManagementCachePKCS8Workflow.php',
     'PhabricatorAuthManagementLDAPWorkflow' => 'applications/auth/management/PhabricatorAuthManagementLDAPWorkflow.php',
     'PhabricatorAuthManagementListFactorsWorkflow' => 'applications/auth/management/PhabricatorAuthManagementListFactorsWorkflow.php',
@@ -2363,6 +2365,7 @@ phutil_register_library_map(array(
     'PhabricatorHelpDocumentationController' => 'applications/help/controller/PhabricatorHelpDocumentationController.php',
     'PhabricatorHelpEditorProtocolController' => 'applications/help/controller/PhabricatorHelpEditorProtocolController.php',
     'PhabricatorHelpKeyboardShortcutController' => 'applications/help/controller/PhabricatorHelpKeyboardShortcutController.php',
+    'PhabricatorHelpMainMenuBarExtension' => 'applications/help/extension/PhabricatorHelpMainMenuBarExtension.php',
     'PhabricatorHeraldApplication' => 'applications/herald/application/PhabricatorHeraldApplication.php',
     'PhabricatorHighSecurityRequestExceptionHandler' => 'aphront/handler/PhabricatorHighSecurityRequestExceptionHandler.php',
     'PhabricatorHomeApplication' => 'applications/home/application/PhabricatorHomeApplication.php',
@@ -2480,6 +2483,7 @@ phutil_register_library_map(array(
     'PhabricatorMailSetupCheck' => 'applications/config/check/PhabricatorMailSetupCheck.php',
     'PhabricatorMailTarget' => 'applications/metamta/replyhandler/PhabricatorMailTarget.php',
     'PhabricatorMailgunConfigOptions' => 'applications/config/option/PhabricatorMailgunConfigOptions.php',
+    'PhabricatorMainMenuBarExtension' => 'view/page/menu/PhabricatorMainMenuBarExtension.php',
     'PhabricatorMainMenuSearchView' => 'view/page/menu/PhabricatorMainMenuSearchView.php',
     'PhabricatorMainMenuView' => 'view/page/menu/PhabricatorMainMenuView.php',
     'PhabricatorManagementWorkflow' => 'infrastructure/management/PhabricatorManagementWorkflow.php',
@@ -2724,6 +2728,7 @@ phutil_register_library_map(array(
     'PhabricatorPeopleLogQuery' => 'applications/people/query/PhabricatorPeopleLogQuery.php',
     'PhabricatorPeopleLogSearchEngine' => 'applications/people/query/PhabricatorPeopleLogSearchEngine.php',
     'PhabricatorPeopleLogsController' => 'applications/people/controller/PhabricatorPeopleLogsController.php',
+    'PhabricatorPeopleMainMenuBarExtension' => 'applications/people/extension/PhabricatorPeopleMainMenuBarExtension.php',
     'PhabricatorPeopleNewController' => 'applications/people/controller/PhabricatorPeopleNewController.php',
     'PhabricatorPeopleNoOwnerDatasource' => 'applications/people/typeahead/PhabricatorPeopleNoOwnerDatasource.php',
     'PhabricatorPeopleOwnerDatasource' => 'applications/people/typeahead/PhabricatorPeopleOwnerDatasource.php',
@@ -3091,6 +3096,7 @@ phutil_register_library_map(array(
     'PhabricatorSettingsAdjustController' => 'applications/settings/controller/PhabricatorSettingsAdjustController.php',
     'PhabricatorSettingsApplication' => 'applications/settings/application/PhabricatorSettingsApplication.php',
     'PhabricatorSettingsMainController' => 'applications/settings/controller/PhabricatorSettingsMainController.php',
+    'PhabricatorSettingsMainMenuBarExtension' => 'applications/settings/extension/PhabricatorSettingsMainMenuBarExtension.php',
     'PhabricatorSettingsPanel' => 'applications/settings/panel/PhabricatorSettingsPanel.php',
     'PhabricatorSetupCheck' => 'applications/config/check/PhabricatorSetupCheck.php',
     'PhabricatorSetupCheckTestCase' => 'applications/config/check/__tests__/PhabricatorSetupCheckTestCase.php',
@@ -5615,6 +5621,7 @@ phutil_register_library_map(array(
     'PHUIListItemView' => 'AphrontTagView',
     'PHUIListView' => 'AphrontTagView',
     'PHUIListViewTestCase' => 'PhabricatorTestCase',
+    'PHUIMainMenuView' => 'AphrontView',
     'PHUIObjectBoxView' => 'AphrontView',
     'PHUIObjectItemListExample' => 'PhabricatorUIExample',
     'PHUIObjectItemListView' => 'AphrontTagView',
@@ -5863,6 +5870,7 @@ phutil_register_library_map(array(
     'PhabricatorAuthListController' => 'PhabricatorAuthProviderConfigController',
     'PhabricatorAuthLoginController' => 'PhabricatorAuthController',
     'PhabricatorAuthLoginHandler' => 'Phobject',
+    'PhabricatorAuthMainMenuBarExtension' => 'PhabricatorMainMenuBarExtension',
     'PhabricatorAuthManagementCachePKCS8Workflow' => 'PhabricatorAuthManagementWorkflow',
     'PhabricatorAuthManagementLDAPWorkflow' => 'PhabricatorAuthManagementWorkflow',
     'PhabricatorAuthManagementListFactorsWorkflow' => 'PhabricatorAuthManagementWorkflow',
@@ -6631,6 +6639,7 @@ phutil_register_library_map(array(
     'PhabricatorHelpDocumentationController' => 'PhabricatorHelpController',
     'PhabricatorHelpEditorProtocolController' => 'PhabricatorHelpController',
     'PhabricatorHelpKeyboardShortcutController' => 'PhabricatorHelpController',
+    'PhabricatorHelpMainMenuBarExtension' => 'PhabricatorMainMenuBarExtension',
     'PhabricatorHeraldApplication' => 'PhabricatorApplication',
     'PhabricatorHighSecurityRequestExceptionHandler' => 'PhabricatorRequestExceptionHandler',
     'PhabricatorHomeApplication' => 'PhabricatorApplication',
@@ -6748,6 +6757,7 @@ phutil_register_library_map(array(
     'PhabricatorMailSetupCheck' => 'PhabricatorSetupCheck',
     'PhabricatorMailTarget' => 'Phobject',
     'PhabricatorMailgunConfigOptions' => 'PhabricatorApplicationConfigOptions',
+    'PhabricatorMainMenuBarExtension' => 'Phobject',
     'PhabricatorMainMenuSearchView' => 'AphrontView',
     'PhabricatorMainMenuView' => 'AphrontView',
     'PhabricatorManagementWorkflow' => 'PhutilArgumentWorkflow',
@@ -7037,6 +7047,7 @@ phutil_register_library_map(array(
     'PhabricatorPeopleLogQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
     'PhabricatorPeopleLogSearchEngine' => 'PhabricatorApplicationSearchEngine',
     'PhabricatorPeopleLogsController' => 'PhabricatorPeopleController',
+    'PhabricatorPeopleMainMenuBarExtension' => 'PhabricatorMainMenuBarExtension',
     'PhabricatorPeopleNewController' => 'PhabricatorPeopleController',
     'PhabricatorPeopleNoOwnerDatasource' => 'PhabricatorTypeaheadDatasource',
     'PhabricatorPeopleOwnerDatasource' => 'PhabricatorTypeaheadCompositeDatasource',
@@ -7488,6 +7499,7 @@ phutil_register_library_map(array(
     'PhabricatorSettingsAdjustController' => 'PhabricatorController',
     'PhabricatorSettingsApplication' => 'PhabricatorApplication',
     'PhabricatorSettingsMainController' => 'PhabricatorController',
+    'PhabricatorSettingsMainMenuBarExtension' => 'PhabricatorMainMenuBarExtension',
     'PhabricatorSettingsPanel' => 'Phobject',
     'PhabricatorSetupCheck' => 'Phobject',
     'PhabricatorSetupCheckTestCase' => 'PhabricatorTestCase',
diff --git a/src/applications/auth/application/PhabricatorAuthApplication.php b/src/applications/auth/application/PhabricatorAuthApplication.php
index dfa1be6f75..a9831b20e3 100644
--- a/src/applications/auth/application/PhabricatorAuthApplication.php
+++ b/src/applications/auth/application/PhabricatorAuthApplication.php
@@ -38,48 +38,6 @@ final class PhabricatorAuthApplication extends PhabricatorApplication {
     return array();
   }
 
-  public function buildMainMenuItems(
-    PhabricatorUser $user,
-    PhabricatorController $controller = null) {
-
-    $items = array();
-
-    if ($user->isLoggedIn()) {
-      $item = id(new PHUIListItemView())
-        ->addClass('core-menu-item')
-        ->setName(pht('Log Out'))
-        ->setIcon('fa-sign-out')
-        ->setWorkflow(true)
-        ->setHref('/logout/')
-        ->setSelected(($controller instanceof PhabricatorLogoutController))
-        ->setAural(pht('Log Out'))
-        ->setOrder(900);
-      $items[] = $item;
-    } else {
-      if ($controller instanceof PhabricatorAuthController) {
-        // Don't show the "Login" item on auth controllers, since they're
-        // generally all related to logging in anyway.
-      } else {
-        $uri = new PhutilURI('/auth/start/');
-        if ($controller) {
-          $path = $controller->getRequest()->getPath();
-          $uri->setQueryParam('next', $path);
-        }
-        $item = id(new PHUIListItemView())
-          ->addClass('core-menu-item')
-          ->setName(pht('Log In'))
-          // TODO: Login icon?
-          ->setIcon('fa-sign-in')
-          ->setHref($uri)
-          ->setAural(pht('Log In'))
-          ->setOrder(900);
-        $items[] = $item;
-      }
-    }
-
-    return $items;
-  }
-
   public function getApplicationGroup() {
     return self::GROUP_ADMIN;
   }
diff --git a/src/applications/auth/extension/PhabricatorAuthMainMenuBarExtension.php b/src/applications/auth/extension/PhabricatorAuthMainMenuBarExtension.php
new file mode 100644
index 0000000000..47264517e0
--- /dev/null
+++ b/src/applications/auth/extension/PhabricatorAuthMainMenuBarExtension.php
@@ -0,0 +1,73 @@
+<?php
+
+final class PhabricatorAuthMainMenuBarExtension
+  extends PhabricatorMainMenuBarExtension {
+
+  const MAINMENUBARKEY = 'auth';
+
+  public function isExtensionEnabledForViewer(PhabricatorUser $viewer) {
+    return true;
+  }
+
+  public function buildMainMenus() {
+    $viewer = $this->getViewer();
+
+    if ($viewer->isLoggedIn()) {
+      return array(
+        $this->buildLogoutMenu(),
+      );
+    }
+
+    $controller = $this->getController();
+    if ($controller instanceof PhabricatorAuthController) {
+      // Don't show the "Login" item on auth controllers, since they're
+      // generally all related to logging in anyway.
+      return array();
+    }
+
+    return array(
+      $this->buildLoginMenu(),
+    );
+  }
+
+  private function buildLogoutMenu() {
+    $controller = $this->getController();
+
+    $is_selected = ($controller instanceof PhabricatorLogoutController);
+
+    $bar_item = id(new PHUIListItemView())
+      ->addClass('core-menu-item')
+      ->setName(pht('Log Out'))
+      ->setIcon('fa-sign-out')
+      ->setWorkflow(true)
+      ->setHref('/logout/')
+      ->setSelected($is_selected)
+      ->setAural(pht('Log Out'));
+
+    return id(new PHUIMainMenuView())
+      ->setOrder(900)
+      ->setMenuBarItem($bar_item);
+  }
+
+  private function buildLoginMenu() {
+    $controller = $this->getController();
+
+    $uri = new PhutilURI('/auth/start/');
+    if ($controller) {
+      $path = $controller->getRequest()->getPath();
+      $uri->setQueryParam('next', $path);
+    }
+
+    $bar_item = id(new PHUIListItemView())
+      ->addClass('core-menu-item')
+      ->setName(pht('Log In'))
+      ->setIcon('fa-sign-in')
+      ->setHref($uri)
+      ->setAural(pht('Log In'));
+
+    return id(new PHUIMainMenuView())
+      ->setOrder(900)
+      ->setMenuBarItem($bar_item);
+  }
+
+}
diff --git a/src/applications/help/application/PhabricatorHelpApplication.php b/src/applications/help/application/PhabricatorHelpApplication.php
index b1f66b02cd..deeae7fa94 100644
--- a/src/applications/help/application/PhabricatorHelpApplication.php
+++ b/src/applications/help/application/PhabricatorHelpApplication.php
@@ -25,84 +25,4 @@ final class PhabricatorHelpApplication extends PhabricatorApplication {
     );
   }
 
-  public function buildMainMenuItems(
-    PhabricatorUser $user,
-    PhabricatorController $controller = null) {
-
-    $application = null;
-    if ($controller) {
-      $application = $controller->getCurrentApplication();
-    }
-
-    $items = array();
-
-    $help_id = celerity_generate_unique_node_id();
-
-    Javelin::initBehavior(
-      'aphlict-dropdown',
-      array(
-        'bubbleID' => $help_id,
-        'dropdownID' => 'phabricator-help-menu',
-        'applicationClass' => __CLASS__,
-        'local' => true,
-        'desktop' => true,
-        'right' => true,
-      ));
-
-    $item = id(new PHUIListItemView())
-      ->setIcon('fa-life-ring')
-      ->addClass('core-menu-item')
-      ->setID($help_id)
-      ->setOrder(200);
-
-    $hide = true;
-    if ($application) {
-      $help_name = pht('%s Help', $application->getName());
-        $item
-          ->setName($help_name)
-          ->setHref('/help/documentation/'.get_class($application).'/')
-          ->setAural($help_name);
-      $help_items = $application->getHelpMenuItems($user);
-      if ($help_items) {
-        $hide = false;
-      }
-    }
-    if ($hide) {
-      $item->setStyle('display: none');
-    }
-    $items[] = $item;
-
-    return $items;
-  }
-
-  public function buildMainMenuExtraNodes(
-    PhabricatorUser $viewer,
-    PhabricatorController $controller = null) {
-
-    $application = null;
-    if ($controller) {
-      $application = $controller->getCurrentApplication();
-    }
-
-    $view = null;
-    if ($application) {
-      $help_items = $application->getHelpMenuItems($viewer);
-      if ($help_items) {
-        $view = new PHUIListView();
-        foreach ($help_items as $item) {
-          $view->addMenuItem($item);
-        }
-      }
-    }
-
-    return phutil_tag(
-      'div',
-      array(
-        'id' => 'phabricator-help-menu',
-        'class' => 'phabricator-main-menu-dropdown phui-list-sidenav',
-        'style' => 'display: none',
-      ),
-      $view);
-  }
-
 }
diff --git a/src/applications/help/extension/PhabricatorHelpMainMenuBarExtension.php b/src/applications/help/extension/PhabricatorHelpMainMenuBarExtension.php
new file mode 100644
index 0000000000..f12714b5ac
--- /dev/null
+++ b/src/applications/help/extension/PhabricatorHelpMainMenuBarExtension.php
@@ -0,0 +1,70 @@
+<?php
+
+final class PhabricatorHelpMainMenuBarExtension
+  extends PhabricatorMainMenuBarExtension {
+
+  const MAINMENUBARKEY = 'help';
+
+  public function isExtensionEnabledForViewer(PhabricatorUser $viewer) {
+    return true;
+  }
+
+  public function buildMainMenus() {
+    $application = $this->getApplication();
+    if (!$application) {
+      return array();
+    }
+
+    $viewer = $this->getViewer();
+    $help_links = $application->getHelpMenuItems($viewer);
+    if (!$help_links) {
+      return array();
+    }
+
+    $help_id = celerity_generate_unique_node_id();
+
+    Javelin::initBehavior(
+      'aphlict-dropdown',
+      array(
+        'bubbleID' => $help_id,
+        'dropdownID' => 'phabricator-help-menu',
+        'local' => true,
+        'desktop' => true,
+        'right' => true,
+      ));
+
+    $help_name = pht('%s Help', $application->getName());
+
+    $help_item = id(new PHUIListItemView())
+      ->setIcon('fa-life-ring')
+      ->addClass('core-menu-item')
+      ->setID($help_id)
+      ->setName($help_name)
+      ->setHref('/help/documentation/'.get_class($application).'/')
+      ->setAural($help_name);
+
+    $view = new PHUIListView();
+    foreach ($help_links as $help_link) {
+      $view->addMenuItem($help_link);
+    }
+
+    $dropdown_menu = phutil_tag(
+      'div',
+      array(
+        'id' => 'phabricator-help-menu',
+        'class' => 'phabricator-main-menu-dropdown phui-list-sidenav',
+        'style' => 'display: none',
+      ),
+      $view);
+
+    $help_menu = id(new PHUIMainMenuView())
+      ->setOrder(200)
+      ->setMenuBarItem($help_item)
+      ->appendChild($dropdown_menu);
+
+    return array(
+      $help_menu,
+    );
+  }
+
+}
diff --git a/src/applications/people/application/PhabricatorPeopleApplication.php b/src/applications/people/application/PhabricatorPeopleApplication.php
index d1cb552e18..45599907c8 100644
--- a/src/applications/people/application/PhabricatorPeopleApplication.php
+++ b/src/applications/people/application/PhabricatorPeopleApplication.php
@@ -123,48 +123,6 @@ final class PhabricatorPeopleApplication extends PhabricatorApplication {
     return $status;
   }
 
-  public function buildMainMenuItems(
-    PhabricatorUser $user,
-    PhabricatorController $controller = null) {
-
-    $items = array();
-
-    if ($user->isLoggedIn() && $user->isUserActivated()) {
-      $profile = id(new PhabricatorPeopleQuery())
-        ->setViewer($user)
-        ->needProfileImage(true)
-        ->withPHIDs(array($user->getPHID()))
-        ->executeOne();
-      $image = $profile->getProfileImageURI();
-
-      $item = id(new PHUIListItemView())
-        ->setName($user->getUsername())
-        ->setHref('/p/'.$user->getUsername().'/')
-        ->addClass('core-menu-item')
-        ->setAural(pht('Profile'))
-        ->setOrder(100);
-
-      $classes = array(
-        'phabricator-core-menu-icon',
-        'phabricator-core-menu-profile-image',
-      );
-
-      $item->appendChild(
-        phutil_tag(
-          'span',
-          array(
-            'class' => implode(' ', $classes),
-            'style' => 'background-image: url('.$image.')',
-          ),
-          ''));
-
-      $items[] = $item;
-    }
-
-    return $items;
-  }
-
-
   public function getQuickCreateItems(PhabricatorUser $viewer) {
     $items = array();
 
diff --git a/src/applications/people/extension/PhabricatorPeopleMainMenuBarExtension.php b/src/applications/people/extension/PhabricatorPeopleMainMenuBarExtension.php
new file mode 100644
index 0000000000..a92c5ba235
--- /dev/null
+++ b/src/applications/people/extension/PhabricatorPeopleMainMenuBarExtension.php
@@ -0,0 +1,49 @@
+<?php
+
+final class PhabricatorPeopleMainMenuBarExtension
+  extends PhabricatorMainMenuBarExtension {
+
+  const MAINMENUBARKEY = 'people';
+
+  public function buildMainMenus() {
+    $viewer = $this->getViewer();
+
+    // TODO: This should get cached.
+
+    $profile = id(new PhabricatorPeopleQuery())
+      ->setViewer($viewer)
+      ->needProfileImage(true)
+      ->withPHIDs(array($viewer->getPHID()))
+      ->executeOne();
+    $image = $profile->getProfileImageURI();
+
+    $bar_item = id(new PHUIListItemView())
+      ->setName($viewer->getUsername())
+      ->setHref('/p/'.$viewer->getUsername().'/')
+      ->addClass('core-menu-item')
+      ->setAural(pht('Profile'));
+
+    $classes = array(
+      'phabricator-core-menu-icon',
+      'phabricator-core-menu-profile-image',
+    );
+
+    $bar_item->appendChild(
+      phutil_tag(
+        'span',
+        array(
+          'class' => implode(' ', $classes),
+          'style' => 'background-image: url('.$image.')',
+        ),
+        ''));
+
+    $profile_menu = id(new PHUIMainMenuView())
+      ->setOrder(100)
+      ->setMenuBarItem($bar_item);
+
+    return array(
+      $profile_menu,
+    );
+  }
+
+}
diff --git a/src/applications/settings/application/PhabricatorSettingsApplication.php b/src/applications/settings/application/PhabricatorSettingsApplication.php
index da0daf65d2..2608cabd88 100644
--- a/src/applications/settings/application/PhabricatorSettingsApplication.php
+++ b/src/applications/settings/application/PhabricatorSettingsApplication.php
@@ -40,26 +40,4 @@ final class PhabricatorSettingsApplication extends PhabricatorApplication {
     return self::GROUP_UTILITIES;
   }
 
-  public function buildMainMenuItems(
-    PhabricatorUser $user,
-    PhabricatorController $controller = null) {
-
-    $items = array();
-
-    if ($user->isLoggedIn() && $user->isUserActivated()) {
-      $selected = ($controller instanceof PhabricatorSettingsMainController);
-      $item = id(new PHUIListItemView())
-        ->setName(pht('Settings'))
-        ->setIcon('fa-wrench')
-        ->addClass('core-menu-item')
-        ->setSelected($selected)
-        ->setHref('/settings/')
-        ->setAural(pht('Settings'))
-        ->setOrder(400);
-      $items[] = $item;
-    }
-
-    return $items;
-  }
-
 }
diff --git a/src/applications/settings/extension/PhabricatorSettingsMainMenuBarExtension.php b/src/applications/settings/extension/PhabricatorSettingsMainMenuBarExtension.php
new file mode 100644
index 0000000000..21534c4237
--- /dev/null
+++ b/src/applications/settings/extension/PhabricatorSettingsMainMenuBarExtension.php
@@ -0,0 +1,29 @@
+<?php
+
+final class PhabricatorSettingsMainMenuBarExtension
+  extends PhabricatorMainMenuBarExtension {
+
+  const MAINMENUBARKEY = 'settings';
+
+  public function buildMainMenus() {
+    $controller = $this->getController();
+    $is_selected = ($controller instanceof PhabricatorSettingsMainController);
+
+    $bar_item = id(new PHUIListItemView())
+      ->setName(pht('Settings'))
+      ->setIcon('fa-wrench')
+      ->addClass('core-menu-item')
+      ->setSelected($is_selected)
+      ->setHref('/settings/')
+      ->setAural(pht('Settings'));
+
+    $settings_menu = id(new PHUIMainMenuView())
+      ->setMenuBarItem($bar_item)
+      ->setOrder(400);
+
+    return array(
+      $settings_menu,
+    );
+  }
+
+}
diff --git a/src/view/page/menu/PhabricatorMainMenuBarExtension.php b/src/view/page/menu/PhabricatorMainMenuBarExtension.php
new file mode 100644
index 0000000000..8b863c835c
--- /dev/null
+++ b/src/view/page/menu/PhabricatorMainMenuBarExtension.php
@@ -0,0 +1,88 @@
+<?php
+
+abstract class PhabricatorMainMenuBarExtension extends Phobject {
+
+  private $viewer;
+  private $application;
+  private $controller;
+
+  public function setViewer(PhabricatorUser $viewer) {
+    $this->viewer = $viewer;
+    return $this;
+  }
+
+  public function getViewer() {
+    return $this->viewer;
+  }
+
+  public function setApplication(PhabricatorApplication $application) {
+    $this->application = $application;
+    return $this;
+  }
+
+  public function getApplication() {
+    return $this->application;
+  }
+
+  public function setController(PhabricatorController $controller) {
+    $this->controller = $controller;
+    return $this;
+  }
+
+  public function getController() {
+    return $this->controller;
+  }
+
+  final public function getExtensionKey() {
+    return $this->getPhobjectClassConstant('MAINMENUBARKEY');
+  }
+
+  public function isExtensionEnabled() {
+    return true;
+  }
+
+  public function isExtensionEnabledForViewer(PhabricatorUser $viewer) {
+    if (!$viewer->isLoggedIn()) {
+      return false;
+    }
+
+    if (!$viewer->isUserActivated()) {
+      return false;
+    }
+
+    // Don't show menus for users with partial sessions. This usually means
+    // they have logged in but have not made it through MFA, so we don't want
+    // to show notification counts, saved queries, etc.
+    if (!$viewer->hasSession()) {
+      return false;
+    }
+
+    if ($viewer->getSession()->getIsPartial()) {
+      return false;
+    }
+
+    return true;
+  }
+
+  abstract public function buildMainMenus();
+
+  final public static function getAllExtensions() {
+    return id(new PhutilClassMapQuery())
+      ->setAncestorClass(__CLASS__)
+      ->setUniqueMethod('getExtensionKey')
+      ->execute();
+  }
+
+  final public static function getAllEnabledExtensions() {
+    $extensions = self::getAllExtensions();
+
+    foreach ($extensions as $key => $extension) {
+      if (!$extension->isExtensionEnabled()) {
+        unset($extensions[$key]);
+      }
+    }
+
+    return $extensions;
+  }
+
+}
diff --git a/src/view/page/menu/PhabricatorMainMenuView.php b/src/view/page/menu/PhabricatorMainMenuView.php
index 1dc8466df3..54ba622f80 100644
--- a/src/view/page/menu/PhabricatorMainMenuView.php
+++ b/src/view/page/menu/PhabricatorMainMenuView.php
@@ -30,7 +30,7 @@ final class PhabricatorMainMenuView extends AphrontView {
     require_celerity_resource('sprite-main-header-css');
 
     $header_id = celerity_generate_unique_node_id();
-    $menus = array();
+    $menu_bar = array();
     $alerts = array();
     $search_button = '';
     $app_button = '';
@@ -41,7 +41,7 @@ final class PhabricatorMainMenuView extends AphrontView {
       if (array_filter($menu)) {
         $alerts[] = $menu;
       }
-      $menus = array_merge($menus, $dropdowns);
+      $menu_bar = array_merge($menu_bar, $dropdowns);
       $app_button = $this->renderApplicationMenuButton($header_id);
       $search_button = $this->renderSearchMenuButton($header_id);
     } else {
@@ -73,13 +73,69 @@ final class PhabricatorMainMenuView extends AphrontView {
     }
 
     $applications = PhabricatorApplication::getAllInstalledApplications();
+
+    $menus = array();
+    $controller = $this->getController();
     foreach ($applications as $application) {
-      $menus[] = $application->buildMainMenuExtraNodes(
+      $app_actions = $application->buildMainMenuItems(
         $user,
-        $this->getController());
+        $controller);
+      $app_extra = $application->buildMainMenuExtraNodes(
+        $user,
+        $controller);
+
+      foreach ($app_actions as $action) {
+        $menus[] = id(new PHUIMainMenuView())
+          ->setMenuBarItem($action)
+          ->setOrder($action->getOrder());
+      }
+
+      if ($app_extra !== null) {
+        $menus[] = id(new PHUIMainMenuView())
+          ->appendChild($app_extra);
+      }
     }
 
-    $application_menu = $this->renderApplicationMenu();
+    $extensions = PhabricatorMainMenuBarExtension::getAllEnabledExtensions();
+    foreach ($extensions as $extension) {
+      $extension->setViewer($user);
+
+      $controller = $this->getController();
+      if ($controller) {
+        $extension->setController($controller);
+        $application = $controller->getCurrentApplication();
+        if ($application) {
+          $extension->setApplication($application);
+        }
+      }
+    }
+
+    foreach ($extensions as $key => $extension) {
+      if (!$extension->isExtensionEnabledForViewer($extension->getViewer())) {
+        unset($extensions[$key]);
+      }
+    }
+
+    foreach ($extensions as $extension) {
+      foreach ($extension->buildMainMenus() as $menu) {
+        $menus[] = $menu;
+      }
+    }
+
+    $menus = msort($menus, 'getOrder');
+    $bar_items = array();
+    foreach ($menus as $menu) {
+      $menu_bar[] = $menu;
+
+      $item = $menu->getMenuBarItem();
+      if ($item === null) {
+        continue;
+      }
+
+      $bar_items[] = $item;
+    }
+
+    $application_menu = $this->renderApplicationMenu($bar_items);
     $classes = array();
     $classes[] = 'phabricator-main-menu sprite-main-header';
     $classes[] = 'phabricator-main-menu-background';
@@ -98,7 +154,7 @@ final class PhabricatorMainMenuView extends AphrontView {
         $aural,
         $application_menu,
         $search_menu,
-        $menus,
+        $menu_bar,
       ));
   }
 
@@ -174,21 +230,8 @@ final class PhabricatorMainMenuView extends AphrontView {
         ''));
   }
 
-  public function renderApplicationMenu() {
+  private function renderApplicationMenu(array $bar_items) {
     $user = $this->getUser();
-    $controller = $this->getController();
-
-    $applications = PhabricatorApplication::getAllInstalledApplications();
-
-    $actions = array();
-    foreach ($applications as $application) {
-      $app_actions = $application->buildMainMenuItems($user, $controller);
-      foreach ($app_actions as $action) {
-        $actions[] = $action;
-      }
-    }
-
-    $actions = msort($actions, 'getOrder');
 
     $view = $this->getApplicationMenu();
 
@@ -199,13 +242,13 @@ final class PhabricatorMainMenuView extends AphrontView {
     $view->addClass('phabricator-dark-menu');
     $view->addClass('phabricator-application-menu');
 
-    if ($actions) {
+    if ($bar_items) {
       $view->addMenuItem(
         id(new PHUIListItemView())
           ->setType(PHUIListItemView::TYPE_LABEL)
           ->setName(pht('Actions')));
-      foreach ($actions as $action) {
-        $view->addMenuItem($action);
+      foreach ($bar_items as $bar_item) {
+        $view->addMenuItem($bar_item);
       }
     }
 
diff --git a/src/view/phui/PHUIMainMenuView.php b/src/view/phui/PHUIMainMenuView.php
new file mode 100644
index 0000000000..7d5910dd7b
--- /dev/null
+++ b/src/view/phui/PHUIMainMenuView.php
@@ -0,0 +1,31 @@
+<?php
+
+final class PHUIMainMenuView extends AphrontView {
+
+  private $menuItem;
+  private $extraContent = array();
+  private $order;
+
+  public function setMenuBarItem(PHUIListItemView $menu_item) {
+    $this->menuItem = $menu_item;
+    return $this;
+  }
+
+  public function getMenuBarItem() {
+    return $this->menuItem;
+  }
+
+  public function setOrder($order) {
+    $this->order = $order;
+    return $this;
+  }
+
+  public function getOrder() {
+    return $this->order;
+  }
+
+  public function render() {
+    return $this->renderChildren();
+  }
+
+}